WO2022029376A1

WO2022029376A1 - Method for supervising the energy of an electrical system provided with controllable loads

Info

Publication number: WO2022029376A1
Application number: PCT/FR2021/051258
Authority: WO
Inventors: Vincent COURTECUISSE; Léo COUTARD; Benoît ROBYNS; Arnaud DAVIGNY; Abderrahman BENCHEKROUN
Original assignee: Geredis Deux Sevres; Yncrea Hauts De France
Priority date: 2020-08-03
Filing date: 2021-07-07
Publication date: 2022-02-10
Also published as: FR3113204B1; FR3113204A1

Abstract

A method for supervising an electrical system (100) comprising loads (1062, 1064), a network (108) and sources (110), the loads being connected to the network via a transformer (1042, 1044,1046) having a high to medium voltage, which is supplied by at least one transformer (1022, 1024) and at least one local source (110), the method comprising acquiring data at different points of the system, and calculating supervision setpoints from the acquired data, according to an operating mode of the supervisor.

Description

DESCRIPTION

Title: PROCESS FOR ENERGY SUPERVISION OF AN ELECTRICAL SYSTEM EQUIPPED WITH CONTROLLED LOADS

Technical area

The invention lies in the field of electrical system supervision methods.

The invention also relates to an electrical supervision device and a system comprising the supervision device according to the invention. Finally, it relates to a computer program product implementing the supervision method according to the invention.

State of the prior art

For several years now, electrical energy distribution networks have been at the heart of energy and environmental developments affecting our society. Indeed, many applications exploit the electric vector in order to increase their energy efficiency. This is particularly the case for electric vehicles or heating by heat pumps. The reduction in the energy consumption of households and industries is often accompanied by an increase in the electricity share of this consumption. The electrical distribution network is therefore seeing an increase in the development of its use. At the same time, the domestic or industrial consumer supplied by the distribution network participates more and more in the production of electrical energy, often of renewable origin. This production does not necessarily coincide with electricity consumption; energy is then sent back to the distribution network, or even the transmission network. In the absence of control of these developments, the constraints on the structures would lead to the reinforcement of the distribution network by increasing the number and dimensions of the lines and electrical substations with high costs and harmful consequences for the environment. This strategy would also be a real brake on the development of electric vehicles, while the major advantage of electric vehicles is their low CO2 emissions. In fact, the CO2 emissions of this type of vehicle depend on the CO2 content of the electrical energy supplying them, the ideal being that these vehicles be charged using renewable energy.

Methods for supervising an electrical network are known in the prior art, such as that described by document US8401709B2 which relates to a system making it possible to dynamically manage and control the energy resources distributed in a transport/distribution network.

However, this solution is not completely satisfactory, because the management system does not take into account the electrical state of the distribution network in the dynamic control of the distributed energy resources. Also, the management system does not offer to integrate a network reconfiguration strategy.

Disclosure of Invention

According to the first aspect of the invention, there is proposed a method for supervising an electrical system comprising an electrical network supplied by at least one high to medium voltage transformer, and electrical loads supplied via medium transformers at low voltage and comprising at least one controllable load, local energy sources.

The method according to the first aspect of the invention comprises the following steps:

- acquisition E11 of average rms values, over a predetermined time interval, of the voltage and current at high to medium voltage transformers in order to calculate their active and reactive powers,

- acquisition E12 of average effective values, over said predetermined time interval, of the active voltage and current at the head of each feeder connected to the high to medium voltage transformers in order to calculate the active and reactive powers,

- determination E13 of the difference between the acquisitions at a current instant and a prior forecast of these quantities, and performance of the following comparison: o if said difference is less than or equal to a predetermined threshold, selection of a first mode, o if said difference is greater than said predetermined threshold, selection of a second mode,

- a step of calculating controllable load supervision setpoints, said supervision setpoints being determined at the current instant, o in the first selected mode, from an overall power profile of the loads, which has been predetermined as a function power forecasts at high to medium voltage transformers, o in the second mode selected, from the values acquired at the current time of the power at high to medium voltage transformers and the state of charge of the controllable load.

The method according to the first aspect of the invention further comprises a step prior to a step E5 of applying to the electrical system said supervision instructions resulting from said calculation, comprising the steps of:

- calculate E3 a virtual state of a digital model of the electrical system at the current time and by applying the calculated supervision instructions, said virtual state being represented by the estimated voltages and currents at the connection points of the medium to low transformers local voltage and energy sources from the acquisitions made in step E12, and from the electrical properties of said digital model, and performance of the following comparison: o if the virtual state thus calculated falls within the domain of operation of the network, apply said supervision instructions, o otherwise, modify said supervision instructions by considering the sensitivity of the voltage and currents of the connection points of the medium to low voltage transformers in relation to the power of the loads connected downstream, and reapplying said step of calculating the virtual state of the digital model at the subsequent instant from said supervision instructions mod ified. According to one possibility, the method for supervising an electrical system according to the first aspect of the invention further comprises the following steps:

- acquisition of values, over said predetermined time interval, of the active and reactive powers, at the level of a first subassembly of the system, each of the electrical loads and local energy sources of said first subassembly being equipped with a means of remote reading,

- acquisition of the history of energy metering data over a second time interval of each of the electrical loads and local energy sources not belonging to the first subset.

In particular, the supervision method of claim can be provided with electrical loads of a second subset of the part of electrical loads which have no sensor or remote reading means, the method according to the first aspect of the invention comprising an additional step of reconstitution and recording in a memory of the temporal power curve of each of said electrical loads of the second subset, said calculation of supervision instructions taking into account on the one hand said acquired data and on the other apart from said time curves.

Advantageously, the method for supervising an electrical system according to the first aspect of the invention may comprise at least one local energy source equipped with a remote reading means, and an acquisition of the active and reactive powers at the level of these sources. local energy sources, the step of calculating the virtual state further determining a virtual state of a digital model of the electrical system at the current instant, by modifying the active and reactive power setpoints at the level of said sources of energy by considering the sensitivity of the voltage and current of their connection points with respect to the active and reactive power injected, and reapplying said step of calculating the virtual state of the digital model by applying said modified supervision instructions.

According to a second aspect of the invention, there is proposed a device for supervising an electrical system comprising acquisition means configured to acquire the various data implemented in a step of a method according to any one of the preceding claims, calculation means configured to perform the calculations performed by the calculation steps of said method and actuating means configured to apply the various supervision instructions of said method.

According to a third aspect of the invention, an electrical system is proposed comprising a device for supervising said electrical system in accordance with the second aspect of the invention.

According to a final aspect of the invention, a computer program product is proposed, downloadable from a communication network and/or stored on a computer-readable medium and/or executable by a microprocessor, and loadable into an internal memory of a computing unit, comprising program code instructions which, when executed by the computing unit, implement the steps of the method according to the first aspect of the invention, or one or more of its improvements.

Description of figures

Other advantages and particularities of the invention will appear on reading the detailed description of implementations and in no way limiting embodiments, with regard to the appended drawings in which:

- [Fig. 1] Figure 1 schematically represents a system according to one embodiment of the invention,

- [Fig. 2] Figure 2 schematically represents a method according to one embodiment of the invention,

- [Fig. 3] Figure 3 represents more precisely one of the steps of the process shown in Figure 2.

Description of embodiments

The embodiments described below being in no way limiting, variants of the invention may in particular be considered comprising only a selection of characteristics described, subsequently isolated from the other characteristics described, if this selection of characteristics is sufficient. to confer a technical advantage or to differentiate the invention from the state of the prior art. This selection includes at least one characteristic, preferably functional without structural details, or with only part of the structural details if only this part is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.

In the figures an element appearing in several figures retains the same reference.

Figure 1 illustrates an embodiment of a system 1 according to the invention.

The system according to the invention comprising an electrical system 100 and a supervision device 200 according to the invention of the electrical system 100.

This description uses the notions of high voltage level B (HVB), high voltage level A (HV), also called medium voltage, and low voltage (LV) domains.

In France, the level B high voltage field targets voltages above 50 kV.

In France, the level A high voltage field targets voltages greater than 1 kv and less than 50 kv.

In France, the low voltage field targets voltages below 1000V.

Since similar delimitations of voltage ranges exist in other countries, reference should be made to the standard applicable to electrical transmission and distribution networks to delimit the different areas.

For example, in the United States, these three areas are referred to respectively as high voltage, medium voltage, and low voltage. More precisely, the ANSI C84.1 -1989 standard separates the sub-domains as follows: high voltage, for the voltage range from 69 kV to 230 kV, medium voltage, for the voltage range from 600 V to 69 kV, low voltage for voltages below 600 V.

By medium to low voltage voltage transformer, the present description aims at a transformer suitable for transforming a voltage in the medium voltage domain into a voltage in the low voltage domain. According to the vocabulary of those skilled in the art, the medium to low voltage voltage transformer is connected both to a level A secondary distribution board on the side of the level A high voltage domain, and to a board main low voltage distribution side of the low voltage area. In France, the medium to low voltage voltage transformer is also referred to as MV/LV transformer by those skilled in the art.

The electrical network is supplied on the one hand by at least one high to medium voltage transformer, and on the other hand by a plurality of local energy sources. In this description, the term local means that the source is connected to the MV or LV voltage range

By high to medium voltage transformer, the present description aims at a transformer suitable for transforming a voltage in the high voltage domain into a voltage in the medium voltage domain. According to the vocabulary of those skilled in the art, the high to medium voltage voltage transformer is connected both to a level B delivery station on the level B high voltage domain side, and to a main high voltage distribution board. level A voltage on the side of the level A high voltage domain.

By nature of a local energy source, this description aims, in a non-limiting way, at wind and photovoltaic energy sources connected to the network. This description also considers the return of energy to the network by an electric vehicle, which is then seen as a source of energy.

The electrical system 100 includes:

- two high to medium voltage transformers, respectively 1022 and 1024, arranged within an HTB/MV substation referenced 102, also called a source substation,

- three medium to low voltage transformers, respectively 1042, 1044 and 1046,

- two charges, respectively 1062 and 1064,

- an electrical network 108, functionally arranged between the two high to medium voltage transformers, respectively 1022 and 1024, and the two loads, respectively 1062 and 1064,

- a renewable energy source such as wind power 110,

- three remote-controlled switches 1122, 1124, 1126., 12 remote-controlled switches, a switch at the MV starting head + two in-line switches (1128 and 1146) + MV panel switch 1126 + transformer switch 1122 and 1124.

Of course, there may be one or more high to medium voltage transformers, two or more medium to low voltage transformers, one or more loads, etc.

The wind-type renewable energy source 110 is not necessary for the implementation of the invention and is only introduced to illustrate a local source of energy.

The electrical network 108 is supplied on the one hand by the two high to medium voltage transformers, respectively 1022 and 1024

More precisely, the remote-controlled switches 1122 and 1124 are normally closed (but represented normally open in the diagram), and carry the current from the transformer 1022, respectively 1024, towards a main MV distribution board 1082, respectively 1084.

Remote switch 1126 is normally open. However, it is possible to reconfigure the network, by closing switch 1126 as soon as one of the two switches 1122 or 1124 is open. The main MV distribution board 1082, respectively 1084, can then be supplied by another transformer.

The electrical network is also powered by the wind-type renewable energy source 110. For this purpose, the renewable energy source is connected to the main HTA 1082 distribution board.

Each of the transformers, respectively 1042, 1044, from high to medium voltage is connected to the substation 102 via the HTA line, also called the HTA start, arranged between the transformer and the main distribution board 1082 or 1084.

Each of the electrical loads, respectively 1062 and 1064, is connected to a main low voltage distribution board, 1082, respectively 1084, via a transformer, respectively 1042, 1044, from high to low voltage.

A controllable load 1267, for example an electric water heater or an electric vehicle, can also be connected to the main switchboard. distribution 1084 through the intermediary of the transformer 1042 from high to low voltage.

A controllable load is equipment whose power supply can be shifted over time. A domestic hot water tank, an electric radiator, an electric vehicle battery, a swimming pool heat pump is an example of a controllable load.

The load can be controlled by means of specific instructions sent via a supervision system, this control will take into account the state of the network.

The high to low voltage transformer 1046 is connected to the main MV distribution board 1084 via a secondary low voltage distribution board 1086.

As shown, photovoltaic productions, on residential roofs or production parks, respectively 1265 and 1266, can form part of the network.

As shown in the figure, the electrical network also includes another remote-controlled switch 1128 (normally open) arranged to selectively choose the energy supply to the load 1162 from two MV outgoing lines.

As illustrated by the various triangles in the figure, the electrical system 100 further comprises counting or telemetry means.

These metering means can be arranged at a source, such as means 1142, at an MV outgoing level such as means 1144, or even at a load such as means 1146 and 1148, respectively associated with the load 1064 and 1062.

It can be noted that the counter 1148 can be of the electronic counter type and indicate a consumption index.

The remote reading means can be wired, for example by using a telephone line or by using the carrier current online. Alternatively, the remote reading means can be wireless, for example using a GSM type technology, for English Global System for Mobile communications.

However, some loads, not shown, may not have remote reading means.

The supervision device 200 comprises: - acquisition means 202 configured to acquire data from the electrical system 100,

- calculation means 204 configured to perform calculations to determine supervision instructions which will be presented later,

- actuating means 206 configured to apply the various supervision instructions to the electrical system 100.

The supervision device 200 is often called a Supervisory Control and Data Acquisition or SCADA system.

The particularity of the invention lies in particular in the configuration of the calculation means for determining the supervision instructions.

According to one possibility, the supervision device 200 can also comprise reception means 208 (not shown) for electricity pricing.

According to an advantageous possibility, the calculation means 204 can be configured to implement artificial intelligence tools (for example neural networks, fuzzy logic) to determine the supervision instructions from a method according to the invention, and/or pricing of the electricity recovered by the receiving means 208.

Referring to Figure 2, there is shown an example of supervision method P1 according to the invention.

The method P1 includes an acquisition step E1.

The acquisition step E1 comprises the following steps, implemented via the acquisition means 202:

- acquisition E11 of average effective values, over a predetermined time interval (typically 10 minutes), of the active power at the level of the high to medium voltage transformers 1022 and 1024,

- acquisition E12 of values, over the predetermined time interval, of the active and reactive powers, of the voltage and of the current, at the level of at least part of the local energy sources, via the measuring means 1142, - acquisition E13 of values, over a predetermined time interval, active values of the voltage and of the current at the feeder level of the high to medium voltage transformer, via the measuring means 1144,

- optionally, acquisition E14 of values, over the predetermined time interval, of the active and reactive power, of the voltage and of the current at the level of a first subset of the part, each of the electrical loads of the first subset being equipped with a remote reading means, or more generally with a consumption sensor, via the measuring means 1148,

- optionally, acquisition E15 of the energy metering data history over a second time interval for each of the electrical loads not belonging to the first subset,

- optionally, reconstitution and recording E16 in a memory of the temporal load curve of each of the electrical loads of the second subset, the calculation of supervision instructions taking into account on the one hand the acquired data and on the other hand the curves temporal.

The method P1 comprises a step E2 of determining a digital model at the current instant of the electrical system, from the data acquired during the step E1 and of determining supervision instructions (artificial intelligence tools allow consolidate the results and eliminate missing and/or erroneous data).

The method P1 comprises a step E3 comprising a virtual digital application of the supervision instructions to the digital model at the current instant. At the output of step E3, a virtual state of the digital model at a later time is thus determined from a digital model at the current time of the electrical system.

The method P1 includes a step E4 of verifying the compliance of the virtual state at a later time with the network operating domain.

The network operating domain is the space in terms of voltage, thermal constraints of lines and transformers within which the electrical network can operate safely. If the electrical network is switched on operating outside its area of operation, its structure risks being damaged or even destroyed.

If the virtual state at a later time thus calculated falls within the network operating domain, the method P1 continues with a step E5 comprising an application of the supervision instructions to the electrical system 100.

The supervision setpoint can be applied to a load, an energy source or an energy storage.

Advantageously, the supervision setpoint can be a power modulation setpoint. The power modulation can, for example, be a shedding instruction. A load, a source, or a storage can be erased.

If the state of the virtual network at a subsequent time thus calculated does not fall within the network operating domain, the method P1 continues with a step E6 of determining modified supervision setpoints.

Step E6 is then continued by step E3, which then includes a digital application of the supervision setpoints modified to the digital model at the current instant.

The supervision instructions can include instructions for controlling the state of the switches. It is thus possible to reconfigure the electrical network.

The supervision setpoints can include setpoints for controlling the state of local energy sources. The command instructions can for example include instructions for clipping the state of a renewable energy source. By renewable energy source, this description designates, for example, a wind, photovoltaic, small hydropower source (over the water), or waste, by waste recovery, for example anaerobic digestion.

When the electrical system includes at least one storage device, the supervision instructions can then include instructions for controlling the state of at least one storage device.

At the output of step E3, a new virtual state of the digital model is thus determined at a later time from the current state and the modified setpoints. The verification of step E4 is then performed. With the method P1 according to the invention, the electrical network is modeled according to a very fine level of granularity, and it is possible to deliver various supervision instructions, such as power modulation instructions, control of the state of the switches, controlling the state of the local energy sources or even controlling the state of at least one storage device.

Figure 3 illustrates more precisely the operation of the part of step E2 for determining supervision instructions.

Step E2 includes a first sub-step E20 of determining a digital model at the current instant of the electrical system, from the data acquired during step E1. The data acquired in step E1 can be consolidated and it is possible to overcome missing and/or erroneous data. Several classic techniques based on AI (for Artificial Intelligence) exist. They are not further described, because they are not the subject of the invention.

According to a second sub-step E21 of step E2, the method comprises a determination of the difference between data representative of the state of the electrical system resulting from the digital model at the current instant and a forecast of the state of the current electrical system.

The data representative of the state of the electrical system at the current time comes from step E1 and includes in particular:

- the average effective values acquired, over a predetermined time interval, of the voltage and the current at the level of the high to medium voltage transformer,

- the acquired values, over said predetermined time interval, of the active voltage and current at the feeder level of said high to medium voltage transformer.

The forecast of the state of the electrical system at the current instant can be carried out according to various methods, one of which is detailed below.

Sub-step E21 further includes the following comparison step:

- if said difference is less than or equal to a predetermined threshold, selection of a first mode, if said difference is greater than said predetermined threshold, selection of a second mode.

Typically, the predetermined threshold is around 5%.

When the first mode M1 is selected, the supervision setpoints are determined, in a sub-step E22, from a predetermined load profile Po comprising a series of supervision setpoints. The predetermined load profile can be achieved by various methods, one of which is detailed below.

When the second mode M2 is selected, the supervision setpoints are determined, in a sub-step E23, from the acquired active values of the voltage and of the current at the level of the high to medium voltage transformer as well as the state of charge estimated VE/BEC.

In the particular context of controllable loads of the electric vehicle and hot water tank type, the state of charge can be estimated, for electric vehicles, according to their charging times and customer utilization rates modeled by normal laws, while for hot water tanks, the state of charge is estimated from energy needs determined from customer hot demand statistics.

The fuzzy logic describes the state of these different quantities by membership functions and a set of rules is defined in order to maximize the load of the VE/BEC during the backflow periods and limit it in the opposite case. Finally, an additional layer makes sure to meet the daily energy needs of the VE/BEC by forcing the load if necessary. The additional layer makes it possible to guarantee charging of an electric vehicle for a predetermined time, for example no later than 6:30 a.m. for vehicles charged at homes and 3 p.m. for those charged at workplaces, if the estimated charging time is from 4:00 a.m.

Power forecasting at the source substation can be carried out using artificial neural networks using the history of measurements and weather parameters to establish correlations and predict future values.

These forecasts then make it possible to determine the load profiles of the controllable loads using a conventional optimization algorithm. The purpose of this is to minimize the cost of transporting energy with the constraint to meet the energy needs of the controllable loads before the end of the day. The load profiles obtained are finally communicated to the supervision system to be used in the sub-step E22.

Such an optimization algorithm can for example be the successive quadratic optimization making it possible to solve a nonlinear optimization problem.

The inputs to the algorithm are the power profile provided for the source substation and the data required to calculate the energy delivery cost, such as the subscribed power, tariff coefficients, etc.

The outputs are the load profiles of the controllable loads.

The objective function to be minimized is the cost of daily energy transmission, subject to the constraints of a full charge of the controllable loads before predetermined deadlines.

Of course, the invention is not limited to the examples which have just been described and many adjustments can be made to these examples without departing from the scope of the invention. In addition, the different features, forms, variants and embodiments of the invention may be associated with each other in various combinations insofar as they are not incompatible or exclusive of each other.

Claims

Claims Method for supervising an electrical system (100) comprising an electrical network (108) supplied by at least one high to medium voltage transformer (1022, 1024), and electrical loads (1062, 1064...) supplied by medium to low voltage transformers (1042, 1044, 1046) and comprising at least one controllable load, and local energy sources (110), said supervision method comprising the following steps:

- acquisition (E11 ) of average rms values, over a predetermined time interval, of the voltage and current at the high to medium voltage transformers in order to calculate their active and reactive powers,

- acquisition (E12) of average rms values, over said predetermined time interval, of the voltage and current at the head of each feeder connected to the high to medium voltage transformers in order to calculate their active and reactive powers,

- determination (E13) of the difference between the acquisitions (E11) and (E12) at a current instant and a prior forecast of these quantities, and carrying out the following comparison: o if said difference is less than or equal to a predetermined threshold , selection of a first mode (M1), o if said difference is greater than said predetermined threshold, selection of a second mode (M2),

- a calculation step

(E2) controllable load supervision setpoints, said supervision setpoints being determined at the current instant, o (E22): in the first selected mode, from an overall power profile of the controllable loads, which has been predetermined according to the power forecasts at the level of the high to medium voltage transformers o (E23): in the second selected mode, from the values acquired (E11) at the current instant of the power at the level high to medium voltage transformers and from the state of charge of the controllable loads, the method further comprising a step prior to a step of applying (E5) to the electrical system said supervision instructions resulting from said calculation, comprising the steps of:

- calculate

(E3) a virtual state of a digital model of the electrical system at the current time by applying the calculated supervision instructions, said virtual state being represented by the estimated voltages and currents at the connection points of the medium to low voltage transformers and local energy sources from the acquisitions made in (E12) and the electrical properties of said numerical model, and carrying out the comparison

(E4) following: o if the virtual state thus calculated falls within the network's operating domain, apply

(E5) said supervision setpoints, o if not, modify (E6) said supervision setpoints by considering the sensitivity of the voltage and current of the connection points of the medium to low voltage transformers in relation to the power of the loads connected downstream , and reapplying said step of calculating the virtual state of the digital model by applying said modified supervision instructions. Method for supervising an electrical system (100) according to the preceding claim, further comprising the following steps:

- acquisition (E14) of values, over said predetermined time interval, of the active and reactive powers, at the level of a first subset of the system, each of the electrical loads and of the local energy sources of said first subset being equipped with a means of remote reading,

- acquisition (E15) of the history of the energy metering data over a second time interval of each of the electrical loads and local energy sources not belonging to the first subset. Supervision method according to the preceding claim, in which the electric loads of a second subset of the part of electric loads do not have a sensor or remote reading means, the method comprising an additional step (E16) of reconstitution and recording in a memory of the temporal power curve of each of said electrical loads of the second subset, said calculation of supervision instructions taking into account on the one hand said acquired data and on the other hand said temporal curves. Method for supervising an electrical system (100) according to one of the preceding claims, comprising at least one local energy source equipped with remote reading means, and an acquisition (E14) of the active and reactive powers at the level of these energy sources, the step of calculating the virtual state (E3) further determining a virtual state of a digital model of the electrical system at the current instant, by modifying the active and reactive power setpoints at the level of said energy sources by considering the sensitivity of the voltage and current of their connection points with respect to the active and reactive power injected, and reapplying said step of calculating the virtual state of the digital model by applying said supervision instructions modified. Supervision device (200) of an electrical system (100) comprising acquisition means (202) configured to acquire the various data implemented in a step of a method according to any one of the preceding claims, means (204) configured to perform the calculations performed by the calculation steps of said method and actuating means (206) configured to apply the various supervision instructions of said method.

6. Electrical system (100) comprising a supervision device (200) of said electrical system according to the preceding claim.

7. Computer program product, downloadable from a communication network and/or stored on a computer-readable medium and/or executable by a microprocessor, and loadable into an internal memory of a calculation unit, comprising code instructions programs which, when they are executed by the computing unit, implement the steps of the method according to any one of the preceding claims for the method of supervising an electrical system.